In a large soup pot, sauté onions, bell peppers and garlic in oil until onions begin to brown around the edges, about 7 minutes.
Add the tomatoes and juice, broth, pepper, and red pepper flakes. Simmer, uncovered, over low heat about 15 minutes.
Add rice, cover and simmer until rice is tender about 30 minutes. Add the peanut butter; whisk until smooth. Heat to a simmer and serve immediately, garnished with chopped roasted peanuts.